A pathologist has been unable to determine how a senior Tory whose body was found in a Glastonbury Festival VIP toilet died, an inquest heard today.
Christopher Shale, 56, a close friend of David Cameron, was discovered slumped in a cubicle in the backstage area yesterday morning.
The Prime Minister's constituency chairman had been reported as missing by worried family members at 900-acre Worthy Farm on Saturday.
The inquest, which lasted just a few minutes, was opened and adjourned until a later date by East Somerset Coroner Tony Williams.
The hearing, which was held at Wells Town Hall, heard that Mr Shale was found within the festival's Orange Zone and declared dead at 9.17am by an emergency care practitioner.
Mr Shale's wife formally identified his body later that morning.
Coroner's officer Ben Batley told the inquest that a post mortem examination was carried out yesterday and the preliminary cause of death was "unascertained".
Mr Batley said further toxicology tests would be carried out to establish how Mr Shale died.
The coroner said that he was adjourning the inquest until a later date.
He added: "As a result of me having opened this inquest I am content to release the body to the family."
No members of Mr Shale's family were present at the inquest.
It is feared Mr Shale's body may have lain undiscovered for up to 10 hours.
Police found the businessman's body as he was quoted in the Mail on Sunday bemoaning difficulties his party faced in recruiting new members.
He was reported to have written: "No reason to join. Lots of reasons not to."
Earlier today Downing Street confirmed it had contacted Mr Shale on Saturday to warn him that the note he had written had been leaked to the newspaper".
Mr Cameron said he was "devastated" as he described Mr Shale as a valued friend and a "big rock" in his life.
Confusion reigned at the site after festival founder Michael Eavis said the wealthy businessman's death could be a "suicide situation".
But police dismissed the claim, with sources saying he was thought to have suffered a heart attack.
A police spokesman said: "The results of the post-mortem combined with the inquiries conducted into the circumstances surrounding the death indicate it is not suspicious."
Mr Eavis expressed his "deepest sympathy" as the police probe was launched.
Mr Shale was staying with his family in a Winnebago surrounded by a host of celebrities and performers.
Mr Cameron, the MP for Witney, said he and wife Samantha were great friends of Mr Shale's.
"Sam and I were devastated to hear the news about Christopher," the Prime Minister said.
The West Oxfordshire Conservative Association chairman was "a great friend and has been a huge support over the last decade" in the constituency, Mr Cameron added.
"A big rock in my life has suddenly been rolled away," he said.
A distraught woman, staying in the backstage area between the Pyramid and other stages, was seen being comforted by officers shortly after the discovery at 9am.
Police confirmed several relatives were at the site.
Mr Eavis sent his thoughts to family and friends, before adding: "We work very closely with the police, medical and other emergency services to ensure that the festival is as safe as possible for all 170,000 people on the site."
A police cordon, patrolled by dozens of officers and security guards, was erected in the area where festival production teams and some performers stay.
A host of celebrities were also camped in the vicinity, with Wayne and Coleen Rooney understood to have been staying in a nearby luxury RV.
Mr Shale and his relatives were apparently staying next to The Times columnist Caitlin Moran.
The writer tweeted: "Woke up to find the man in the Winnebago next to us died. Bit of a grim start to the morning."
Revellers reacted with shock as they were told the area was "a crime scene".
Tom Waite, 35, from Cheddar, was among those staying in the VIP area.
He said: "It's just awful for his family."
Mr Shale was the chief executive of Oxford Resources Ltd, a cost reduction company based in Chipping Norton, Oxfordshire.
He was previously chief executive of MSG Communications.
He is listed on the website of eurosceptic think-tank OpenEurope as a supporter and was a director of the Centre for Policy Studies.
Most revellers carried on partying unaware as the festival came to a close in sweltering conditions, with more than 50,000 fans turning out for a performance from American star Beyonce.